(1) mix the wave files into a new file and then play this file (PocketC is too slow to do this in real time). I have a lot of code that does that in PocketC - write again if you need it.

(2) there is a free Wave mixing library out, and Kevin has written a wrapper DLL library around it so you can use it from within PocketC. Unfortunately you will need PocketC V3 for this. I tested the library and it works well, except that it has sluggish response (considerable and varying delay between calling the mix function and the time when it actually starts playing). If your application is not extremely timing-critical, it should work though.